Consumer electronic products, such as notebooks, personal digital assistants (PDA), mobile phones, MP3 players, and so on, are trending toward smaller sizes continuously, which thereby promotes higher demand for easily-portable electric power connectors, for example, a power supply, a battery charger, or a transformer. Therefore, the electric power connectors of consumer electronic products need to be made with smaller sizes and less weight, and more convenient for shipment. Furthermore, they must be durable in order to sustain long-term carrying and frequent usage. Each of the consumer electronic products needs a plug on the electric power connectors or on the product itself to supply power thereto, and thus the plug is a necessary unit. Various kinds of plugs come out recently for the consumer electronic products or the electric power connectors to be carried conveniently, such as rotatable plugs, foldable plugs, or retractable plugs.
For instance, a conventional electric power connector includes a housing and a plug. The housing further has a concave storage confinement near the top edge of the housing. The plug is mainly composed of a rod having a tenon on each side thereof, two first pins and two second pins. The first pins and the second pins respectively have holes corresponding to the tenon for inserting the tenon to make the connection of the first pins, the second pins and the rod. Each side wall of the concave storage confinement has a spring receptacle containing a spring. The ends of the spring are respectively in contact with a side of the spring receptacle and a cavity disposed in each of the first pins via a fixing element. The plug is positioned in the concave storage confinement by the resilience force of the springs and folded by adjusting the first pins to drive the second pins and rotate the rod. Thus, the plug is electrically connected to the circuit board mounted inside the housing.
Many conventional foldable, rotatable or retractable plugs similar to the above plug have a major difficulty in the mechanical design. The conventional foldable or rotatable fixtures usually have weak mechanical structure for attaching to either the housing or other members of the plug connector. The weak attachment structure may cause the foldable or rotatable unit to be damageable, less reliable and even dangerous to the user and may also affect the establishment or maintenance of a good electric contact. Moreover, conventional converters for different national standards usually couple with the plug through slots in the converters. Because there is no fixing mechanism between the converters and the plug, the converters often fall off the plug when in use, thereby causing the decrease in safety of the plug. Thus, there is still a demand for providing a rotatable plug cooperatable with a converter that is durable and safe and can overcome the above shortcomings.